下降(descent)

Crisis would be the right term to describe the ____________ in many animal species.

A:minimization B:restriction C:descent D:decline

There is less crime now than there used to be. It seems that there is a ______ in the crime rate.

A:slope B:incline C:descent D:decline

A result of nuclear explosion,fallout is the descent of minute particles of radioactive materiaI through the atmosphere.

A:charged B:heavy C:tiny D:lost

A:result of nuclear explosion, fallout is the descent of minute particles of radioactive material through the atmosphere. charged B:heavy C:tiny D:lost

When there is a(n) {{U}}slump{{/U}} in a country it is difficult to do trade, and many people are out of work.

A:descent B:depression C:inertia D:decrease